Shootlets of Rosa multiflora L. cv. Montse were cultured in vitro with four different levels of sucrose (0, 1, 3 and 5%). Chloroplasts of shootlets grown in a medium without sucrose contained numerous, large plastoglobuli and were lacking in starch granules. The size and number of starch granules increased with the level of sucrose in the culture medium. Starch content in leaves of shootlets grown with 5% sucrose was higher (ca 1, 3%) than those grown with 3% (ca 0, 45%) and 1% sucrose (ca 0, 27%). Starch might be used by the in vitro shootlets during the acclimation period.
"Reduced 14 CO 2 assimilation was observed in cauliflower plants cultured in vitro in a 3 % sucrose environment (Grout and Crisp 1977). Capellades et al. (1991) also reported that increased sucrose in the culture medium significantly reduced the net photosynthetic rate. In Pfaffia glomerata , the omission of sucrose from the culture medium increased the assimilation of photosynthetic carbon (Iarema et al. 2012). "
[Show abstract][Hide abstract] ABSTRACT: This study assessed the ecophysiological aspects of the in vitro multiplication of ‘Golden’ papaya in response to different light qualities, ventilation systems and sucrose concentrations related to photosynthesis, chlorophyll fluorescence, water balance and growth. The treatments were performed in a complete, randomised split-plot design with four replicates. These treatments consisted of white and red light, closed and ventilated culture systems and four sucrose concentrations (10, 20, 30 and 40 g L-1) in the culture medium. The lowest plantlet water loss rate was obtained using the ventilated culture system. The photochemical damage was attributable to the reduced maximum PS II quantum yield and the efficiency of the oxygen-evolving complex (OEC). The increase in the production of papaya dry biomass was due to the exogenous carbon source, the sucrose that was added to the culture medium. In this study, there was no photosynthetic carbon assimilation (Aactual, actual photosynthetic rate) or oxygen evolution (Apot, potential photosynthetic rate) due to the damage caused by the presence of sucrose in the culture medium to the photochemical capacity of the oxygen-evolving complex (OEC) and PS II activity. Further studies are needed using a sucrose concentration below 10 g L-1 in association with the increased irradiance of the culture chamber (red lights) as well as carbon dioxide enrichment (over 400 uL L-1 of air). These conditions may stimulate the autotrophic metabolism of this species for in vitro cultivation and increase the rate of biomass production.
Theoretical and Experimental Plant Physiology 03/2014; 1(1):1. DOI:10.1007/s40626-014-0026-y
"Peso total da matéria fresca de plântulas de cafeeiro 'Acaiá' oriundas de embriões zigóticos retirados de frutos em diferentes estádios de desenvolvimento e cultivados em meio de cultura com diferentes concentrações de sacarose. os níveis de sacarose devem ser mantidos em torno de 30 g L -1 na fase que antecede a aclimatização, para a planta acumular reservas e enfrentar o meio ambiente (Capellades et al., 1991). Andrade et al. (2001), estudando a resposta de embriões de Coffea arabica e C. canephora, observaram que a eficiente germinação e desenvolvimento das plântulas ocorreu em meio de cultivo MS que continha 30 g L -1 de sacarose. "
[Show abstract][Hide abstract] ABSTRACT: In vitro culture offers a controlled system to study the nutritional, physiologic and biochemical processes of embryos in several developmental stages. In this work, the relationship between development stage of the fruit and sucrose concentration in the culture medium for in vitro development of coffee embryos was evaluated. Embryos of Coffea arabica L. cv. Acaiá were excised and inoculated into the culture medium MS with pH adjusted to 5.8. The treatments consisted of the combination of six sucrose concentrations (0, 15, 30, 60, 90 and 120 g L-1) and six developmental stages of the fruit ('pin-head', 'lead', 'green', 'green-yellow', 'cherry' and 'overripe'). After inoculation, the embryos were incubated in growth room at 27 ± 1ºC, photoperiod of 16 hours and 35 µ mol m-2 s-1 of luminous intensity. The experimental design was entirely randomized (6 x 6 factorial), with six repetitions and the parcel constituted by four tubes each. After 60 days, the seedlings were evaluated based on shoot length, total fresh weight of shoot and root. Influences of the sucrose concentrations and the stages of fruit development were observed, and the best results were obtained with embryos excised in the stage 'green' and inoculated in the culture medium supplemented with 51 to 70 g sucrose L-1.
Revista Ceres 12/2011; 58(6):679-684. DOI:10.1590/S0034-737X2011000600001
"The role of starch metabolism during the hardening of plantain plants propagated in TIB was described by our team (Aragón et al. 2006). The carbohydrate accumulation as starch reserves is important for plant survival during hardening phase (Capellades et al. 1991). Both carbohydrates' (sucrose–starch) reserves in plantain leaf and stem, respectively, seem to play an important role during hardening phase (Aragón et al. 2005, 2006). "
[Show abstract][Hide abstract] ABSTRACT: In vitro physiology and carbon metabolism can be affected by the sink–source relationship. The effect of different sucrose concentrations
(10, 30, and 50g L−1), light intensities (80 and 150μmolm−2s−1), and CO2 levels (375 and 1,200μmolmol−1) were tested during plantain micropropagation in temporary immersion bioreactors. Activities of pyruvate kinase, phosphoenol
pyruvate carboxylase, and the photosynthesis rate were recorded. From the morphological and practical point of view, the best
results were obtained when plants were cultured with 30g L−1 sucrose, 80μmolm−2s−1 light intensity, and 1,200μmolmol−1 CO2 concentration. This treatment improved leaf and root development, reduced respiration during in vitro culture, and increased starch level at the end of the hardening phase. In addition to that, the number of competent plants
was increased from 80.0% to 91.0% at the end of the in vitro phase and the survival percentage from 95.71% to 99.80% during ex vitro hardening.
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